Power-transmission chain



E. B. NICHOLS May 2, 1967 POWER-TRANSMISSION CHAIN Filed April 13, 1966 IN V EN TOR.

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map/V576 United States Patent LO 3,316,771 POWER-TRANSMISSION CHAIN Edgar'B. Nichols, 119 Colonial Ave., Moorestown, NJ. 08057 Filed Apr. 13, 1966, Ser. No. 542,376 Claims. (Cl. 74-248) This invention is a continuation-in-part of my copending application Ser. No. 366,708, filed May 12, 1964, and now abandoned.

This invention relates to power-transmission chains, and more particularly to such chains being composed of molded plastic links.

In the conventional silent chains each unit of the chain is composed of a plurality of fiat steel links arranged side by side. Steel links of each unit are secured in overlapping relation to other steel links situated immediately adjacent by a cross pin, thereby forming a complete chain.

This invention relates to an improved power-transmitting chain in which each unit of the chain consists of a solid, generally triangular shaped central portion, having a plurality of planar end projections extending downwardly from two adjacent sides of the central portion. Each end projection, on each side thereof, is further positioned equidistant from each other.

This structure makes it possible to construct the individual parts of the chain with plastic material and yet provide a chain which can easily transmit power safely and drive loads up to twice as great as can safely be driven by a chain of conventional construction with each unit of the same overall size, and made of the same material.

A more complete appreciation of the invention, and many of the attendant advantages thereof will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings:

FIG. 1 is a perspective view of the links and pivot pins making up one form of the invention.

FIG. 2 is a detailed view showing the underside of the link;

FIG. 3 is a side elevation view of the chain and a portion of a sprocket wheel for the chain;

FIG. 4 is a side elevation view of a link of a modified form;

FIG. 5 is a side elevation view of a further modified link;

FIG. 6 is a side elevated view of yet another modified link; and

FIG. 7 is a cross-sectional view of the link depicted in FIG. 6, along lines 66.

Referring to the drawings, this invention relates to a power-transmission chain made up of a series of identical plastic links 1. Each link 1 consists of a generally triangular central portion 3 and a plurality of thin planar end projections 7. The end projections 7 extend downwardly from two sides of the triangular central portion 3. Each end projection 7, on each side of the triangular central portion 3, is arranged in a side by side fashion, equidistant from each other, thereby forming slots 6 of equal width.

The end projections 7 and slots 6, at one end of the link 1, are staggered with respect to the projections and slots at the other end, so that in a chain of the width shown in the drawings, there are five end projections at one end of each link and six at the other end, thereby making it 3,316,771 Patented May 2, 1967 possible for the end projections of one link to slide within the slots of an immediately adjacent link.

Each end portion, on each side ofthe triangular central portion 3, carries. an aperture 8, arranged in axial alignment with each other, for receiving an elongated pivot pin 2. This pivot pin is adapted to lock two links in fixed overlapping relation, and thereby forms a complete chain.

Each pivot pin carries a head 10 at one end and a circumferential groove 11 at the other end for receiving split washer 9.

In FIG. 3, the novel power-transmission chain is depicted as being positioned over a sprocket wheel 16 having peripheral teeth 4.

In FIG. 4, a modified form of the link is illustrated. This form is desirable when the starting load to which the chain is subjected is greater than the running load. As here shown, the axis of the aperture 8 for receiving the pivot pin 2 is below the triangular central portion 3 and, consequently, the load app-lies a bending stress to the central portion, thereby permitting a substantial elongation of the length of chain between the driving and driven sprockets without exceeding the elastic limit of the plastic material.

FIG. 5 illustrates a link having gaps or apertures 15 and 16 extending through the end projections. The particular shape of the gaps is not critical and, accordingly, they may take the shape of a triangle 15 or oval 16. To provide the end projections with a gap would enable the link 1 to become more flexible and, accordingly, more versatile.

FIGS. 6 and 7 illustrate a link having a flange 12 attached to the end projection. The flange is positioned along the outermost edge of the curved end projection, on one planar side, and extends upwardly from the apex 13 of the end projection so as to be adapted to extend into the slot 6 of an immediately adjacent link. Such a flange provides the link with an increased contact surface for engagement with the teeth of the sprocket wheel.

Chains of the construction shown in the drawings are made of plastic material, preferably nylon. Nylon has the advantage of requiring no lubrication and of resisting wear to an unusual degree. Other materials which have been found satisfactory include Mylar, Teflon and Delrin.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

I claim:

1. A power-transmission chain comprising a series of molded plastic units connected together by cross pins, said units comprising elongated solid central sections extending in a direction parallel to the axis of one of the cross pins and across the entire width of the chain, said solid central section having, along its entire length, a generally triangular cross-sectional area in a plane normal to said axis on said one of the cross pins, thereby defining a three-sided central section for reducing the rotational movement of each unit about the cross pins, and a plurality of planar end projections extending outwardly and downwardly from two adjacent sides of each central section, each end projection on each side of the central section being equidistant from the other.

2. The power-transmission chain of claim 1, wherein the molded units are nylon.

3. The power-transmission chain of claim 1, wherein the axis of the cross pin is positioned below the central section.

4. The power-transmission chain of claim 1, wherein each end projection carries a gap extending therethrough.

5. The power-transmission chain of claim 1, wherein each end projection carriesa flange extending outwardly from a planar face of the end projection along its outer edge.

References Cited by the Examiner UNITED STATES PATENTS 818,469 4/1906 Rogers 74--254 4 7/1913 Dodge 74-254 X 10/ 1914 Howson 74251 3/1934 Oakes 74-250 7/1952 Bremer 74-250 11/ 1959 Imse.

FOREIGN PATENTS 1893 Great Britain.

DAVID J. W'ILLIAMOWSKY, Primary Examiner.

J. A. WONG, Assistant Examiner. 

1. A POWER-TRANSMISSION CHAIN COMPRISING A SERIES OF MOLDED PLASTIC UNITS CONNECTED TOGETHER BY CROSS PINS, SAID UNITS COMPRISING ELONGATED SOLID CENTRAL SECTIONS EXTENDING IN A DIRECTION PARALLEL TO THE AXIS OF ONE OF THE CROSS PINS AND ACROSS THE ENTIRE WIDTH OF THE CHAIN, SAID SOLID CENTRAL SECTION HAVING, ALONG ITS ENTIRE LENGTH, A GENERALLY TRIANGULAR CROSS-SECTIONAL AREA IN A PLANE NORMAL TO SAID AXIS ON SAID ONE OF THE CROSS PINS, THEREBY DEFINING 